Recently, there is a growing need for comparison/identification of products for the purpose of quality control and distribution management.
Under the circumstances, an RFID performing data communication via a wireless communication system is incorporated into a product to comprehensively perform a commodity control and loss-prevention, antitheft, forgery prevention, etc. of commodities throughout all the stages of production, logistics, sales, etc. of products. For example, such a technology is proposed that an RFID chip is attached to an object and comparison is performed by using data stored in a memory in the RFID chip, thereby enabling logistics management, authenticity determination, etc. of the object.
It was, however, costly because an RFID chip was to be incorporated into every object. In a case where an object is small, it is often impossible to attach even a generally used tag to the object, and thus less possible to attach a special equipment such as an RFID chip.
Taking the foregoing into consideration, such a technology is proposed that comparison of an object (or individual identification) is performed by a pattern of a predetermined comparison region of an object to which the pattern is provided on the basis that the patterns applied to the individual objects somewhat differ from one another or that patterns include some common parts if the objects are the same kind of objects produced by using the same die, etc. (Patent Literature 1).
Also, as a technology for identifying a nature/type of a surface of an object by determining presence/absence of surface unevenness, such a technology is proposed in which an object is exposed to illumination light, calculation is performed to obtain a degree of change in a spatial direction for a feature amount of reflection light therefrom, and comparison is performed between thus calculated value and previously calculated dictionary data (Patent Literature 2).